Pseudocode demonstrating debouncing.

gistfile1.js

// Pseudocode to demonstrate debouncing
$(".item_column").on("scroll", function(){
 // this function fires way too fast
 getItemsInView();
});

// With debouncing:
$(".item_column").on("scroll", _.debounce(function(){
 // max this function can fire is every 150 milliseconds
 getItemsInView();
}, 150);